Potion or spectrum, which is more reliable for detecting stainless steel?
202 and 304, the price difference between the two is nearly 1,000 yuan, one contains less than 4 nickels, and the other contains 8 nickels. It is difficult to distinguish with the naked eye. However, after dropping a little potion, 304 will hardly change color. And different materials, the color of the potion is also different:
(1) 201: The droplet turns to brown in an instant (1 second);
(2) 202: The droplet turns brownish red in about 15 seconds;
(3) 301: The droplet turns light red after 30 seconds;
(4) 304: The droplet slowly turns light gray over 50 seconds.
The stainless steel potion test is fast and simple, but is this test reliable?
In fact, this simple verification method is only recognized in the building materials industry, but the relevant authoritative quality inspection agency has stated that this method is a test that has not been certified by authority and is not scientific.
Stainless steel does not rust because stainless steel contains a kind of chromium element. The chromium element forms a passivation film with the atmospheric oxide layer. The passivation film protects the metal inside, and the passivation film has a self-repairing ability. Moreover, the chromium, nickel, manganese, and other components contained in different types of stainless steel are quite different, and the performance will also be very different. But the use environment of stainless steel is also more important.
In terms of scientific testing, spectral testing is by far the most reliable method for testing stainless steel. No matter whether it is moved or not, the deviation will not be too large. However, such a detection method is not invulnerable, and the industry must be vigilant against the vulnerabilities traps under scientific detection. It is understood that in the general inspection of stainless steel cold-rolled coils, it is only necessary to use a spectrometer to irradiate the inner and outer two circles of the stainless steel.
Therefore, there has also been a case in the industry: the seller designed to put a layer of high-quality stainless steel on the inner layer and the outer layer, and use inferior stainless steel in the middle, posing as a well-known brand of high-quality stainless steel cold rolled coil to sell to customers. Using shoddy stainless steel to fool the Popper detector, the seller made huge profits from it.
The industry lacks consciousness, so it needs tool testing. Scientific tool detection requires constant patching, leaving no loopholes for criminals to take advantage of the void.